YOICHI, Japan - Climate change has helped make the small Japanese town of Yoichi the toast of Pinot Noir connoisseurs, with gradually warming temperatures encouraging locals to try their hand at the delicate grape variety over the past two decades.

Yoichi was well known as the home of Nikka Whisky. But it burst into the viticultural limelight five years ago, when the 2017 Nana-Tsu-Mori Pinot Noir from the local Domaine Takahiko winery was featured on the wine list of Copenhagen's globally acclaimed Noma restaurant.

A bottle of that prized wine, which once sold for around $30, is now offered by resellers in Japan for about $560. Other wines from the town, which is located on Japan's northernmost island of Hokkaido and now has about 20 wineries and 70 vineyards, have also won their fair share of accolades.

But Yoichi's farmers fret that even before the town's reputation has had a chance to be embraced by mainstream consumers, recent rapid gains in temperatures and potentially more rain during the harvesting season could mean that it will become difficult to grow the Pinot Noir grape here.

"It's like a roller coaster," said Domaine Takahiko owner Takahiko Soga, who founded his winery in 2010.

Soga said he once thought Yoichi's temperatures during the growing season were roughly similar to France's Alsace region, but then they reached levels on par with Burgundy, which produces some of the world's finest Pinot Noirs.

"Then, when I thought we were at Burgundy temperatures, we got closer to Loire or Bordeaux levels this year," he said.

Climate change is roiling many farmers of all types of crops across the world, while blessing only some. Wine producers are no exception, but the Pinot Noir grape is particularly sensitive.

Known for producing elegant transparent wines, the grape can thrive in cool to temperate climates, but its thin skin and tight clusters make it extremely sensitive to even a bit too much sun or rain.

Vexed by birds

Climates of wine-growing regions around the world are classified under the Winkler Index, which is calculated by adding daily average temperatures above 10 °C or growing degree days (GDD) from April to October.

Hokkaido has generally been viewed as having a Region I climate - the coolest of the five Winkler climate groups.

But since 2023, Yoichi's GDD sum has nudged up into Region II territory, according to data from Japan's Meteorological Agency. That's a temperature zone more commonly viewed as suited to medium-bodied reds such as Merlot and Cabernet Sauvignon.

And this year, Yoichi had its hottest summer since record-keeping began, with average temperatures of 22.1 °C between June and August, about 3 degrees higher than the average for the three decades to 2020.

Yoichi's warmer and longer summer seasons increase the chances that Pinot Noir grapes could ripen too quickly, leading to undesirably high sugar and low acid levels. Higher temperatures also make the fruit more prone to damage from rain.

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Yuichi Hirotsu, an award-winning vineyard owner whose family was in 2006 among the first of the town's farmers to plant the classic red, said his Pinot Noir grapes had suffered from rain damage this year.

And another variety he grows, the Austrian Zweigeltrebe, was also severely hit by a particularly heavy downpour in September - something Hirotsu says he hasn't previously seen at the beginning of autumn.

"It took us forever to pick Zweigeltrebe this year because we had to remove damaged grapes one by one," he said.

Also vexing Yoichi's winegrowers has been a marked increase in the number of birds looking to feast on their grapes - a trend they also blame on climate change, saying it has reduced sources of nuts and seeds for the birds in nearby mountains.

Such is the scourge that the sound of firecrackers to scare them away is ever-present in Yoichi.

The need to gain knowledge about coping with climate change was one of the primary reasons behind Yoichi Mayor Keisuke Saito's formation of a "wine accord" with the historic Pinot Noir commune Gevrey-Chambertin in Burgundy this year that will see the two groups exchange know-how on production methods.

In terms of immediate measures, as temperature and humidity control become increasingly challenging, Domaine Takahiko has built an underground wine cellar to store 100 barrels.

Trying new types of Pinot Noir or other kinds of grapes will also be necessary, the farmers believe.

"Pinot Noir might not be the ultimate goal for this town. Varieties like Merlot or Syrah might be what await us in the future," said Soga.